TY - JOUR
T1 - Scanning tunneling spectroscopy of SmFeAsO0.85
T2 - Possible evidence for d-wave order-parameter symmetry
AU - Millo, Oded
AU - Asulin, Itay
AU - Yuli, Ofer
AU - Felner, Israel
AU - Ren, Zhi An
AU - Shen, Xiao Li
AU - Che, Guang Can
AU - Zhao, Zhong Xian
PY - 2008/9/22
Y1 - 2008/9/22
N2 - We report a scanning tunneling spectroscopy investigation of polycrystalline SmFeAsO0.85 having a superconducting transition at 52 K. On large regions of the sample surface the tunneling spectra exhibited V -shaped gap structures with no coherence peaks, indicating degraded surface properties. In some regions, however, the coherence peaks were clearly observed and the V -shaped gaps could be fitted to the theory of tunneling into a d -wave superconductor, yielding gap values between 8 and 8.5 meV corresponding to the ratio 2Δ/KB TC ∼3.55-3.8, which is slightly above the BCS weak-coupling prediction. In other regions the spectra exhibited zero-bias conductance peaks consistent with a d-wave order-parameter symmetry.
AB - We report a scanning tunneling spectroscopy investigation of polycrystalline SmFeAsO0.85 having a superconducting transition at 52 K. On large regions of the sample surface the tunneling spectra exhibited V -shaped gap structures with no coherence peaks, indicating degraded surface properties. In some regions, however, the coherence peaks were clearly observed and the V -shaped gaps could be fitted to the theory of tunneling into a d -wave superconductor, yielding gap values between 8 and 8.5 meV corresponding to the ratio 2Δ/KB TC ∼3.55-3.8, which is slightly above the BCS weak-coupling prediction. In other regions the spectra exhibited zero-bias conductance peaks consistent with a d-wave order-parameter symmetry.
UR - http://www.scopus.com/inward/record.url?scp=52949085843&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.78.092505
DO - 10.1103/PhysRevB.78.092505
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
AN - SCOPUS:52949085843
SN - 1098-0121
VL - 78
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 9
M1 - 092505
ER -